Packet Capture

Collector
generic
#tcpdump -ni fxp0 -s 1500 -w file.pcap
specific host
#tcpdump -ni fxp0 -s 1500 -w file.pcap 'host 192.168.10.10'
specific protocol
#tcpdump -ni fxp0 -s 1500 -w file.pcap 'tcp'
specific port
#tcpdump -ni fxp0 -s 1500 -w file.pcap 'port 80'

..... and a lot more of combination